Rank the four gases (air, exhaled air, gas produced from the decomposition of h2o2, gas from decomposition of nahco3, in order of decreasing concentration of oxygen

Who is better, messi or cristiano, i need this for a chemistry class. asap

If 1.8 l of water is added to 2.5l of a 7.0 molarity koh solution, what is the molarity of the new solution

Some familiar products contain some of the same types of atoms. for instance, the chemical formula for baking soda is nahco 3. the chemical formula for liquid bleach is naclo, and the chemical formula for table salt is nacl. which choice best describes why these three products have some of the same types of atoms in common?